The plug-in-card type liquid purifying and filtering device with prior art comprises the water pump, filtering cylinder and filtering plug-in card. The said filtering plug-in card is installed inside the filtering cylinder. The said water pump pumps the liquid in the water body into the filtering cylinder. After the liquid in the filtering cylinder is purified by the said filtering plug-in card, it will be discharged from the said filtering cylinder and refluxed into the water body. The implementation of purifying treatment is repeated in cycles. The said filtering plug-in card includes the fixed frame and filter installed inside such fixed frame. There are close pinholes on the said filter. Such pinholes are utilized to sieve dirt and impurities inside the liquid flowing through such filter. The commonly used filters are filter cottons with various kinds of permeability. The said filter is chiefly used to execute the liquid filtering treatment. In order to execute the liquid purification treatment, inside the said filter or between two layers of filters is set with filtering materials that are useful to change the water body components and improve the water quality. Such filtering materials enable the water body components to be more suitable to their application environment. For instance, as regards the water body inside the aquarium breeding tank, the said filter materials can adopt granular ones that feature the function of absorbing harmful substances or the ion exchange function, such as active carbon or maifan stone. Besides, the granular filtering materials that can cultivate nitrifying bacteria can be adopted, such as zeolite. The said water body refers to the water body differently held in fixed containers. It can either be the water body stored in reservoirs that is used for the garden irrigation, or the water body inside the aquarium breeding tank. In order to prevent the liquid in the filtering cylinder from splashing, the plug-in-card type liquid purifying and filtering device with prior art is further equipped with the top cap covered at the bunghole of the said filtering cylinder. Obviously, many dirt and impurities will be deposited at the said filtering plug-in card upon long-term usage. Meanwhile, the filtering material inside the said filtering plug-in card needs to periodically be replaced. Therefore, the said filtering plug-in card is a component needing periodic replacement that is detachably set inside the said filtering cylinder in normal conditions.
The plug-in-card type purifying and filtering device with prior art have the following defects and shortcomings:
1. When the said filtering plug-in card is periodically replaced, the disassembled filtering plug-in card always has the liquid inside the filtering cylinder attached. During the replacement, the liquid attached to the said disassembled filtering plug-in card will drip. So it is necessary to clean the drippy liquid in the course of replacing the filtering plug-in card upon the completion of such replacement; in particular, as for the plug-in-card type liquid purifying and filtering device applied to the aquarium breeding tank, such operation of replacing the filtering plug-in card will soak the neighborhood of the aquarium breeding tank, thus affecting the fancy effects and wetting the neighboring ground of the aquarium breeding tank. In order not to affect fanciers and other relevant personnel, the neighborhood of the aquarium breeding tank must be cleaned and wiped upon the replacement of the said filtering plug-in card, thus enabling the process of replacing the said filtering plug-in card to be complicated, overloaded and inconvenient.
2. In the course of applying the said plug-in-card type liquid purifying and filtering device configured with the top cap, the liquid in the said filtering cylinder will splash or vaporizes to the underside of the top cap. When the said filtering plug-in card is replaced or the top cap is otherwise needed to be disassembled, the liquid attached to the underside of the disassembled top cap will similarly drip, thus incurring the issue of complicated and overloaded operation processes and inconvenience.